Due to the progression of the large-scale design in the semiconductor device accompanying the micro-fabrication technology development in the semiconductor manufacturing process, voltage fluctuation may occur in the power supply signal or the ground level signal when the integrated circuit device is activated. The voltage fluctuation deteriorates the reliability of the integrated circuit operation. With a view to solve the above-mentioned problem, in order to analyze the malfunction which causes the error in the integrated circuit, an evaluation method for evaluating the voltage fluctuation in the power supply signal or in the ground level signal is strongly required, in short, a noise evaluation method is strongly required.
Conventionally, the use of the noise evaluation method is mainly limited to the research purpose. Many researches are focused on developing the dedicated purpose test chips wherein both the main large-scale integrated circuit (which turns to be the noise source) and the noise measuring circuit are embedded. However, the conventional noise measuring circuit is arranged in the chip separated from the main large-scale integrated circuit (which turns to be the noise source), as seen in FIG. 11. Therefore, it is difficult to use the conventional noise measuring circuit as a practical-use malfunction analysis circuit in the commercial base large-scale integrated circuit chip because of problems such as the necessity of leading the probe to the target position for the noise detection, the largeness of the layout area, and the largeness of the power consumption.
Under the above-mentioned circumstances, the chip configuration wherein the noise measuring circuit is combined with the main large-scale integrated circuit is known in the conventional technology for detecting the malfunction in the main large-scale integrated circuit accompanying increasing of the noise level in the power supply signal (for example, the prior art document 1). However, the noise measuring circuit described in the prior art document 1 detects the voltage level of the power supply line, compares the detected voltage level with the predetermined threshold voltage level set previously in the circuit, and performs the predetermined procedure when the detected noise level is larger than the predetermined threshold voltage level, so the conventional prevention method is only focused on the instantaneous values of the noise data. Therefore, the temporal transitional series data of the voltage level fluctuation and the noise level fluctuation cannot be obtained. In the conventional technology, it is difficult to perform the malfunction diagnosis or the error analysis for judging whether or not an error is occurred by the noise, and whether or not the timing when the error had occurred corresponds to the timing when the noise had occurred.
[Prior Art Document 1]: Japanese Patent publication No. 2002-222929.